The present invention relates to a capsule filling machine for the production of hard gelatine capsules containing products, preferably pharmaceutical products.
In particular, the pharmaceutical products contained in hard gelatine capsules of the type with a capsule lid and a capsule body to which this text refers are products which are powdered or made from powdered material, such as tablets, micro-tablets or xe2x80x9cpelletsxe2x80x9d, or liquid products.
Generally speaking, a capsule filling machine of the known type currently used basically comprises a central turret, rotating with intermittent or stepping motion, with a plurality of operating units arranged along the edge of the turret and driven by the turret by means of reciprocating drive parts.
Each turret operating unit comprises a support element in the form of a slide which holds one or more capsules to be carried, with the above-mentioned stepping motion, to a plurality of work stations in which successive operating steps take place, according to a known method, such as feeding and angled positioning of the closed capsules, the subsequent opening of each capsule, that is to say, separation of the capsule body from the capsule lid, feeding of a quantity of pharmaceutical product into the capsule body, then closing of each capsule body with the relative capsule lid and, finally, ejection of the closed, filled capsule obtained in this way.
The above-mentioned pharmaceutical product is fed using an operating station consisting of a hopper containing the product, which feeds a rotary drum which has a plurality of cylindrical product dosing holes.
The synchronised stepping rotation of the turret relative to the drum allows the capsule slide support carried on the turret to move opposite the corresponding cylindrical dosing hole in the drum which already holds a dose of product compressed by a piston or pounder.
At this point during the turret dwell period, the slide with the capsule body is moved forward with a radial movement of the turret towards the drum, so that it is positioned under the cylindrical hole and in a feed position, that is to say, so that the dose is released into the capsule body. Then the slide support moves back, again radially towards the central turret, to move clear of the drum, then the turret turns forward one step for the subsequent operating steps.
However, product feed according to the above-mentioned method currently has several disadvantages, in particular due to the mechanical complexity of the slide support radial linear movement from and towards the cylindrical dosing hole in the drum.
The slide support linear movement requires a transition time between slide positioning and the arrival of the cylindrical hole with the quantity of product which is mechanically difficult to achieve and necessitates slide supports with very long operating strokes.
Moreover, in many cases product losses occur, particularly around the seats or bushes which hold the capsule bodies on the slide support, resulting in friction which damages the slide supports and may cause unwanted rotary turret and, consequently, capsule filling machine stops.
The aim of the present invention is, therefore, to overcome the above-mentioned disadvantages in the prior art.
Accordingly the present invention provides a capsule filling machine for the production of hard gelatine capsules of the type with a capsule lid and a capsule body and containing a product, preferably a pharmaceutical product. The machine comprises at least a first rotary station with a stepping motion for supporting and moving at least one capsule body to a second, product feed and dosing station, the second station rotating with a stepping motion synchronised with the first station, and having at least one cylindrical hole containing a dose of the product. Between the first station and the second station there are slide means for supporting and moving the capsule body between a first operating position, in which the capsule body is distanced from a lower end of the cylindrical hole, and a second, operating position, in which the capsule body is exactly below the lower end of the cylindrical hole, allowing the dose of product to be released into the capsule body. The machine is characterised in that the slide means comprise at least a first and at least a second support which operate in conjunction with one another. The first support is carried by the first rotary station and supports at least one capsule body. The second support is carried by the second rotary station and is positioned, in the first operating position, below the end of the cylindrical hole containing the dose, closing the end. There are drive means designed to operate on at least the first support, so that the first support moves forward towards the second support with both radial and transversal motion, until the first support gradually makes contact with the second support, the first support consequently pushing on the second support in such a way that the second support moves backwards from the first operating position to the second operating position, allowing the dose to be released into the capsule body.